Overview
3 g pre-bed lowers core body temperature and improves subjective sleep.
- Dietary protein from animal sources (meat, fish, eggs, dairy) and plant sources (soy, legumes, grains)
- Free-form amino acid powders and capsules
- Targeted pre-workout, recovery, or sleep formulations
- Free-form crystalline powder
- Capsules or tablets
- Pre-mixed recovery or hydration beverages
- Time-release formulations
Mechanism of action
Activates suprachiasmatic NMDA receptors → peripheral vasodilation → core temp drop.
- · Activates suprachiasmatic NMDA receptors → peripheral vasodilation → core temp drop
Effects on the body
Organ system effects
Glycine (Sleep Onset) promotes parasympathetic tone, GABAergic signaling, or melatonergic pathways that facilitate sleep onset and quality.
Evidence-based benefits
Improves sleep quality and morning alertness
Moderate evidencePotential side effects
- · Glycine (Sleep Onset) is generally well-tolerated at evidence-based doses
- · Mild GI discomfort (nausea, loose stools, or bloating) possible at higher intakes
- · Headache or transient fatigue reported by a small fraction of users
- · Allergic or hypersensitivity reaction (rash, itching, swelling)
- · Sleep disturbance if taken late in the day
- · Discontinue and seek medical advice if symptoms are severe, persistent, or include difficulty breathing
Drug interactions
Safety & non-supplemental interactions
Educational summary — always confirm with your clinician or pharmacist before starting, stopping, or combining with prescription therapy.
- ·Alcohol, benzodiazepines, opioids, sedating antihistamines (additive CNS depression)
Supplement interactions
- Magnesium glycinateComplementary GABAergic calming and improved sleep architecture.
- L-theanineReduces sleep latency without sedation.
No specific avoidances listed.
Dosing & bioavailability
Where to buy
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Third-party testedIndependently verified Glycine (Sleep Onset) — look for USP, NSF, or Informed Sport seals on the label for purity and dose accuracy.Glycine (Sleep Onset) third party tested NSF
CapsulesPre-measured Glycine (Sleep Onset) capsules — easiest for travel and consistent daily dosing without scoops or scales.Glycine (Sleep Onset) capsules
PowderBulk unflavored Glycine (Sleep Onset) powder — best cost-per-gram and flexible dosing for stacking or mixing into drinks.Glycine (Sleep Onset) powder unflavored
Best sellersMost-purchased Glycine (Sleep Onset) products on Amazon — a quick way to see what's reviewed widely before you commit.Glycine (Sleep Onset) best sellerScientific evidence8Show studiesHide studies
Glycine ingestion before sleep improves subjective sleep quality
Yamadera W, et al.
Crossover trial of 3 g glycine before bed.
Improved subjective sleep quality and daytime function.
PubMed: Glycine (Sleep Onset) — Improves sleep quality and morning alertness
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